His ideas were wildly popular at the time. He classified people into one of three groups: ectomorphs (tall and skinny), endomorphs (round but solid), or mesomorphs (compact and muscular). Sheldon used thousands of nude photos to build a taxonomy of body shapes called somatotypes. The “posture picture project” was led by William Herbert Sheldon, a psychologist who was, incidentally, the world’s leading authority on American pennies. The official story was that it was to help identify posture problems. Then the student posed for pictures from three angles-front, side, and back.

Once the student disrobed, the men taped metal pins to his or her spine. There were no forms or waivers to sign, no choice to opt out.

One by one, freshmen were led into a room full of men decked in white and instructed to undress. But if you were a student at one of America’s elite universities during the middle of the 20th century, it was really awkward: From the 1940s to the 1960s, incoming students at schools like Yale, Vassar, Harvard, Syracuse, Purdue, and Wellesley were required to pose for a series of nude portraits. Freshman orientation is easily the most awkward part of college.